The present invention relates to a hood assembly for use on conventional heavy and medium duty trucks of the type wherein the hood opens forwardly from the cab to expose the engine compartment and, more particularly, to a hood motion control apparatus including a four-bar linkage for attaching the hood to the truck chassis, with or without a secondary pivot which can be activated to increase the degree of forward tilt of the hood. The hood motion control apparatus provides the advantage that, once the hood has been moved slightly from its position of engagement with the cowl of the vehicle, only a minimal amount of physical effort will be required on the part of the person tilting the hood to move it to a fully open position, as well as other advantages, such as reduced hood weight and improved hood motion control.